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High Dose Ascorbic Acid Treatment of CMT1A

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00484510
Recruitment Status : Completed
First Posted : June 11, 2007
Last Update Posted : March 6, 2013
Muscular Dystrophy Association
Charcot-Marie-Tooth Association
Information provided by (Responsible Party):
Michael E. Shy, MD, Wayne State University

Brief Summary:
This study will look at the impact of ascorbic acid (Vitamin C) on the progression of disease in people with CMT1A as compared to volunteers receiving a placebo. This study will assess whether is it futile to proceed with a larger, longer-term, placebo-controlled study.

Condition or disease Intervention/treatment Phase
Charcot-Marie-Tooth Disease, Type Ia Drug: Ascorbic acid (Vitamin C) Drug: placebo Phase 2 Phase 3

Detailed Description:
Charcot Marie Tooth disease (CMT), or inherited peripheral neuropathies, are among the most frequent heritable disorders, affecting approximately 1 in 2500 people. The most frequent genetic form of CMT is CMT1A. CMT1A is caused by a 1.4 Mb duplication within chromosome 17p11.2 in the region containing the PMP22 gene. Most subjects with CMT1A have a "typical" phenotype characterized by onset in childhood or early adulthood, distal weakness, sensory loss, foot deformities and absent reflexes. How increased expression of PMP22 causes these disabilities is unknown but is currently being investigated in both animal and tissue culture systems. In this study, researchers will evaluate whether ascorbic acid (Vitamin C), administered orally, slows clinical progression of CMT1A and affects the PMP22 mRNA levels of myelinated peripheral nerve fibers obtained from biopsies of glabrous skin.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 110 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Treatment
Official Title: A Randomized, Placebo-controlled, Double Masked 120 Subject "Futility Design" Clinical Trial of Ascorbic Acid Treatment of Charcot Marie Tooth Disease Type 1A.
Study Start Date : April 2007
Actual Primary Completion Date : December 2012
Actual Study Completion Date : December 2012

Arm Intervention/treatment
Experimental: Ascorbic Acid Drug: Ascorbic acid (Vitamin C)
Eight 500 mg capsules/day of ascorbic acid. Subjects will take four (4)capsules each morning and four (4) capsules each evening for 24 months. (Total 4 gr/day).

Placebo Comparator: Placebo Drug: placebo
Eight 500 mg capsules/day of placebo. Subjects will take four (4)capsules each morning and four (4) capsules each evening for 24 months.

Primary Outcome Measures :
  1. Mean change in the CMT Neuropathy Scale following high dose ascorbic acid ingestion, assessed at baseline and every 6 months throughout the trial. [ Time Frame: 25 months per subject from baseline to completion. ]

Secondary Outcome Measures :
  1. Evaluation of PMP22 mRNA levels of myelinated peripheral nerve fibers. [ Time Frame: Baseline and Month 24. ]

Information from the National Library of Medicine

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Ages Eligible for Study:   13 Years to 70 Years   (Child, Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • The subject has CMT1A, defined by the duplication on chromosome 17p11.2 performed by either Pulse Field Gel Electrophoresis or Fluorescence In Situ Hybridization (FISH) by a CLIA certified laboratory, OR the subject has a first or second degree relative with a documented duplication performed by the above methods AND the subject has uniform motor conduction slowing of the median or ulnar nerve between 16 and 30 m/s.
  • The subject is between 13 and 70 years of age.
  • The subject, if 18 years or older, has signed the Informed Consent Form and agrees to follow the stipulations of the protocol.
  • If the subject is less than 18, his or her parents or guardians have signed the Informed Consent Form and agree to follow the stipulations of the protocol. The subject has also signed a written assent form.

Exclusion Criteria:

  • A known neuropathy from another source (For example, diabetes, drug induced, alcohol, etc.)
  • The subject has ever received Vincristine.
  • The subject has a known allergy to ascorbic acid.
  • The subject has ever had kidney stones.
  • The subject has a known history of G6PD deficit.
  • The subject has a history of hemochromatosis.
  • The subject suffers from a serious illness or medical condition that is not stabilized or that could require hospitalization.
  • The subject has a high ascorbic acid level at screening.
  • The subject is pregnant or nursing.
  • The subject, in the opinion of the investigator, is unlikely to comply with the study protocol or is unsuitable for any other reason.
  • The subject participates to another clinical trial or is still within a washout period of a previous clinical trial.
  • The subject is taking neurotoxic medications.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00484510

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United States, Maryland
Johns Hopkins University, Dept of Neurology
Baltimore, Maryland, United States, 21287
United States, Michigan
Wayne State University, Dept of Neurology
Detroit, Michigan, United States, 48201
United States, New York
University of Rochester Medical Center, Dept of Neurology
Rochester, New York, United States, 14642
Sponsors and Collaborators
Wayne State University
Muscular Dystrophy Association
Charcot-Marie-Tooth Association
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Principal Investigator: Richard A Lewis, MD Wayne State University, Dept. of Neurology
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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Responsible Party: Michael E. Shy, MD, Professor, Wayne State University
ClinicalTrials.gov Identifier: NCT00484510    
Other Study ID Numbers: HIC074406MP2F
First Posted: June 11, 2007    Key Record Dates
Last Update Posted: March 6, 2013
Last Verified: March 2013
Keywords provided by Michael E. Shy, MD, Wayne State University:
Ascorbic Acid
Vitamin C
Charcot Marie Tooth
Additional relevant MeSH terms:
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Tooth Diseases
Charcot-Marie-Tooth Disease
Nerve Compression Syndromes
Hereditary Sensory and Motor Neuropathy
Stomatognathic Diseases
Nervous System Malformations
Nervous System Diseases
Heredodegenerative Disorders, Nervous System
Neurodegenerative Diseases
Peripheral Nervous System Diseases
Neuromuscular Diseases
Congenital Abnormalities
Genetic Diseases, Inborn
Ascorbic Acid
Physiological Effects of Drugs
Molecular Mechanisms of Pharmacological Action
Protective Agents